Entity

Time filter

Source Type

Chartres-de-Bretagne, France

Bini D.,CNR Institute of Neuroscience | Damour T.,Institute des Hautes etudes Scientifiques
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2015

Continuing our analytic computation of the first-order self-force contribution to Detweiler's redshift variable we provide the exact expressions of the ninth and ninth-and-a-half post-Newtonian terms. © 2015 American Physical Society. Source


Bini D.,CNR Institute of Neuroscience | Damour T.,Institute des Hautes etudes Scientifiques
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2014

We analytically compute, to linear order in the mass ratio, the "geodetic" spin-precession frequency of a small spinning body orbiting a large (nonspinning) body to the eight-and-a-half post-Newtonian order, thereby extending previous analytical knowledge which was limited to the third post-Newtonian level. These results are obtained applying analytical gravitational self-force theory to the first-derivative level generalization of Detweiler's gauge-invariant redshift variable. We compare our analytic results with strong-field numerical data recently obtained by Dolan et al. [Phys. Rev. D 89, 064011 (2014)]. Our new, high-post-Newtonian-order results capture the strong-field features exhibited by the numerical data. We argue that the spin precession will diverge as ≈-0.14/(1-3y) as the light ring is approached. We transcribe our kinematical spin-precession results into a corresponding improved analytic knowledge of one of the two (gauge-invariant) effective gyrogravitomagnetic ratios characterizing spin-orbit couplings within the effective-one-body formalism. We provide simple, accurate analytic fits both for spin precession and the effective gyrogravitomagnetic ratio. The latter fit predicts that the linear-in-mass-ratio correction to the gyrogravitomagnetic ratio changes sign before reaching the light ring. This strong-field prediction might be important for improving the analytic modeling of coalescing spinning binaries. © 2014 American Physical Society. Source


Bini D.,CNR Institute of Neuroscience | Damour T.,Institute des Hautes etudes Scientifiques
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2014

We extend the analytical determination of the main radial potential describing (within the effective one-body formalism) the gravitational interaction of two bodies beyond the fourth post-Newtonian approximation recently obtained by us. This extension is done to linear order in the mass ratio by applying analytical gravitational self-force theory (for a particle in circular orbit around a Schwarzschild black hole) to Detweiler's gauge-invariant redshift variable. By using the version of black hole perturbation theory developed by Mano, Suzuki and Takasugi, we have pushed the analytical determination of the (linear in mass ratio) radial potential to the sixth post-Newtonian order (passing through 5 and 5.5 post-Newtonian terms). In principle, our analytical method can be extended to arbitrarily high post-Newtonian orders. © 2014 American Physical Society. Source


Bini D.,CNR Institute of Neuroscience | Damour T.,Institute des Hautes etudes Scientifiques
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2014

We analytically compute, to the eight-and-a-half post-Newtonian order, and to linear order in the mass ratio, the radial potential describing (within the effective one-body formalism) the gravitational interaction of two bodies, thereby extending previous analytic results. These results are obtained by applying analytical gravitational self-force theory (for a particle in circular orbit around a Schwarzschild black hole) to Detweiler's gauge-invariant redshift variable. We emphasize the increase in "transcendentality" of the numbers entering the post-Newtonian expansion coefficients as the order increases, in particular we note the appearance of ζ(3) (as well as the square of Euler's constant γ) starting at the seventh post-Newtonian order. We study the convergence of the post-Newtonian expansion as the expansion parameter u=GM/(c2r) leaves the weak-field domain u≪1 to enter the strong field domain u=O(1). © 2014 American Physical Society. Source


Damour T.,Institute des Hautes etudes Scientifiques
Classical and Quantum Gravity | Year: 2015

The 1974 discovery, by Russell A Hulse and Joseph H Taylor, of the first binary pulsar, PSR B1913+16, opened up new possibilities for the study of relativistic gravity. PSR B1913+16, as well as several other binary pulsars, provided direct observational proof that gravity propagates at the velocity of light and has a quadrupolar structure. Binary pulsars also provided accurate tests of the strong-field regime of relativistic gravity. General relativity has passed all of the binary pulsar tests with flying colors. The discovery of binary pulsars also had very important consequences for astrophysics, leading to accurate measurement of neutron star masses, improved understanding of the possible evolution scenarios for the co-evolution of binary stars, and proof of the existence of binary neutron stars emitting gravitational waves for hundreds of millions of years, before coalescing in catastrophic events radiating intense gravitational wave signals, and probably also leading to important emissions of electromagnetic radiation and neutrinos. This article reviews the history of the discovery of the first binary pulsar, and describes both its immediate impact and its longer-term effect on theoretical and experimental studies of relativistic gravity. © 2015 IOP Publishing Ltd. Source

Discover hidden collaborations